The invention concerns a method for encapsulating electrical and/or electronic components in a housing, the components being arranged on a printed circuit or a strip conductor in an assembly, and the assembly is positioned in the housing and is encapsulated with a curing, an electrically insulating molding compound.
The method in question can be used to manufacture any desired electrical or electronic assemblies in a housing. For example, these can be network parts or network modules that are resistant to environmental factors such as submergence and fouling, shock, vibration, etc. However, it should be emphasized here that this can involve any electrical and/or electronic components or assemblies in a housing, and the encapsulation not only provides a sealing against the surroundings, but also, in particular, an electrical insulation within the assembly. Based on such an encapsulation, it is possible to place the electrical and/or electronic components as close together as possible on the integrated circuit or strip conductor, thereby enabling a further miniaturization of the corresponding assemblies.
The above mentioned method is already rather well known from practice, the method being used at atmospheric pressure. In this case, one cannot rule out that the encapsulation contains air bubbles, so that a comprehensive electrical insulation of the individual components is not assured. Moreover, the molding compound does not reach all components, so that one cannot assure a satisfactory embedding and insulation of the components.
Furthermore, electrolytic capacitors have a tendency to outgas during operation and when exposed to heat. If such electrolytic capacitors are not totally encapsulated, or if they are surrounded by air bubbles, the assembly may become damaged and thus malfunction.
The basic problem of the present invention is therefore to organize and modify a method of the kind described above so that the aforementioned problems do not occur, or occur only in an extremely limited extent. The above indicated problem is solved by a method with the features of patent claim 1. Accordingly, the method is characterized such that the encapsulating preferably takes place in a molding chamber at a pressure below atmospheric pressure and the negative pressure is removed after encapsulation and before curing.